How are the Debate Moderators Chosen? The moderators are selected by the CPD.
The CPD uses three criteria to select its moderators: a) familiarity with the
candidates and the major issues of the presidential campaign; b) extensive
experience in live television broadcast news; and c) an understanding that the
debate should focus maximum time and attention on the candidates and their
views. The moderators alone select the questions to be asked, which are not known
to the CPD or to the candidates. They do not meet with the campaigns, nor do the
campaigns have a role in moderator selection. Starting in 1996, the CPD has used
a single moderator for all of its debates in order to keep the focus on the candidates
and their positions. end snip
Seemingly to only choose liberals who don’t seem to want to or can follow the rules they lay out for the debaters.